2.5.2

This is a release candidate for 2.6.0.

In addition to new CMake support by @madebr and many bug fixes, here are the highlights since the last release:

• Added support for playing Ogg files using stb_vorbis, which is now the default Vorbis backend.
  To use libvorbis instead, configure using --disable-music-ogg-stb --enable-music-ogg-vorbis
• Added support for playing FLAC files using dr_flac, which is now the default FLAC music backend.
  To use libflac instead, configure using --disable-music-flac-drflac --enable-music-flac-libflac
• Added support for playing MP3 files using dr_mp3, which is now the default MP3 music backend.
  To use libmpg123 instead, configure using --disable-music-mp3-drmp3 --enable-music-mp3-mpg123
• Added libxmp support for mod music playback. Modplug is still the default backend for MOD music.
  To use libxmp instead, configure using --disable-music-mod-modplug --enable-music-mod-xmp
• Removed support for libmad as a MP3 music backend.
• Removed support for libmikmod as a MOD music backend.
• Added Mix_MasterVolume() for additional volume control over all channels
• Update Mix_Init() return value to match documentation, including MIXER_INIT_* flags for already-initialized modules
• Added Mix_HasMusicDecoder()
• Memory leak fixes and F32 format support to fluidsynth player
• Fixed distorted MIDI playback with FluidSynth if sample rate is out of library's limits
• Added Mix_ModMusicJumpToOrder() for mod music formats
• Enabled module internal loops in modplug player
• Respect original mp3 file offset
• Support setting soundfont via SDL_SOUNDFONTS in OSX native midi
• Fixed mp3 file detection
• Fixes to ogg playback on big-endian devices
• Added functions to get metadata information:
  Mix_GetMusicTitle()
  Mix_GetMusicTitleTag()
  Mix_GetMusicArtistTag()
  Mix_GetMusicAlbumTag()
  Mix_GetMusicCopyrightTag()
• Add functions to get loop point information:
  Mix_GetMusicLoopStartTime()
  Mix_GetMusicLoopEndTime()
  Mix_GetMusicLoopLengthTime()
• Added Mix_GetMusicVolume() and Mix_GetMusicPosition()
• Added Mix_MusicDuration() to return music duration in seconds
• Fixed music_mpg123 seek bug when sample rate of the file and the stream don't match
• Timidity improvements, added Mix_SetTimidityCfg()
• Improved mp3 tag detection/skipping
• Extended support for WAV files
• Allow rmid files be opened by native midi
• Fixed possible crash in win32 native midi
• Prevent clipping due to volume settings in modplug music
• Added looping support for Opus files
• Added looping support for FLAC files
• Improved OGG looping support
• Fixed loading Opus audio as audio chunks